The speculation here is that allocated space is used for Xbox Series X|S storage, and it can't be recovered.

The T700 is for gamers, creatives, and professionals seeking the ultimate in solid-state drive performance that today only a Gen 5 SSD offers. But unless your desktop is a recent, high-performance model that supports this standard, being able to run a PCI Express 5.0 SSD at peak speeds requires a considerable additional investment. You must buy a recent desktop that supports SSDs built on the PCIe 5.0 standard, upgrade an existing recent rig, or build one from scratch. By making such an investment and having the T700 serve as its brains, though, you're future-proofing your entire setup. The M.2 standard is based on the mSATA standard, which uses the existing PCI Express Mini Card (Mini PCIe) form factor and connector. M.2 adds the possibility of larger printed circuit boards (PCBs), allowing longer modules and double-sided component population. Consequently, M.2 SSD modules can provide double the storage capacity within the footprint of an mSATA device. [2] :20,22–23 [4] [13] One last caveat to drop in before we get to our product recommendations surrounds Intel's SSD line. Intel for a while sold a family of M.2-based storage products under the brand name Optane, in two very distinct types of drive. Intel's"Optane SSDs"were SSDs like any other, bootable drives that can serve as a stand-alone boot drive or as secondary storage. They were discontinued for consumers in 2021, but you may still see them around. (Intel sold its SSD business at the end of 2021 to SK Hynix, which spun it off into a new subsidiary, Solidigm.)Know which bus you're on.In a laptop-upgrade scenario, you're almost certainly swapping out one M.2 drive for another, with the intent of gaining capacity. Make sure you know the specifications of the drive coming out of your system—and whether it's reliant on the SATA or PCI Express bus—so you can install the same, presumably roomier kind going in. Computer bus interfaces provided through the M.2 connector are PCI Expressx4 (up to four lanes), Serial ATA3.0, and USB3.0 (a single logical port for each of the latter two). It is up to the manufacturer of the M.2 host or module to select which interfaces are to be supported, depending on the desired level of host support and the module type. Different M.2 connector keying notches denote various purposes and capabilities of both the M.2 hosts and modules, and also prevent the M.2 modules from being inserted into incompatible host connectors. [2] [3] [5]

The process is simple. We're going to wipe and configure the USB drive to be bootable and then copy over the Surface Pro 8 + Windows 11 recovery files to it. Here's how:a b Wassenberg, Paul (19 June 2013). "SATA Express: PCIe Client Storage" (PDF). SATA-IO . Retrieved 2 October 2013. One last caveat to drop in before we get to our product recommendations surrounds Intel's SSD line. Intel for a while sold a family of M.2-based storage products under the brand name Optane, in two very distinct types of drive. Intel's "Optane SSDs" were SSDs like any other, bootable drives that can serve as a stand-alone boot drive or as secondary storage. They were discontinued for consumers in 2021, but you may still see them around. (Intel sold its SSD business at the end of 2021 to SK Hynix, which spun it off into a new subsidiary, Solidigm.)